Declines in Problem Solving and Anosognosia in Amyotrophic Lateral Sclerosis: Application of Guilford's Structure of Intellect Theory

Background: Amyotrophic lateral sclerosis (ALS) is a multi-system disorder in which frontotemporal dysfunction without overt dementia is relatively common. Accordingly, there is need for a valid, brief, motor-free cognitive examination conducive to the ALS Clinic. Objective: To validate a brief examination against a comprehensive neuropsychological battery to determine its sensitivity in identifying deficits in judgment and problem solving. We enrolled 13 individuals with intact brief examinations, 25 individuals with 1 or more impaired brief examination measures, and 18 healthy volunteers. Cognitive brief examination measures were classified into factors based on Guilford's Structure of Intellect theory. Cognitive anosognosia ratios were calculated to examine the degree of unawareness of cognitive deficit. Results: Statistically significant correlations were evidenced for each brief examination and comprehensive examination measure categorized by the same Guilford factor. In comparison to healthy controls, insight to level of cognitive abilities was significantly compromised for cognitively impaired ALS patients, with respect to their ratings of their responses to comprehension tasks assessing convergent and divergent production. Conclusions: Brief examination measures of verbal fluency and problem solving may serve as sensitive indicators of emerging difficulties in ALS patients with frontotemporal dysfunction. The prevalence of cognitive anosognosia warrants further attention because of its impact on treatment compliance, safety and quality of life for ALS patients with frontotemporal dysfunction.